Department of Orthopaedic Sports Medicine, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Straße 22, Munich, Germany.
Arch Orthop Trauma Surg. 2013 Sep;133(9):1233-41. doi: 10.1007/s00402-013-1801-y. Epub 2013 Jul 6.
Blood flow in various organs is determined by an autoregulatory mechanism that guarantees constant organ perfusion over a wide range of arterial blood pressure changes. This physiological principle has been proven for the kidney, brain and intestinal tract, but so far not for bone. This study was carried out to determine whether there is an autoregulatory mechanism of bone or not.
The fluorescent microsphere reference sample method was used to determine blood flow within the bone and kidneys. Eight anesthetized female New Zealand rabbits received left ventricular injections of fluorescent microspheres over a wide range of arterial pressure levels prior to removal of kidney, femur and tibia. Blood flow values were calculated by measurement of fluorescence intensity in kidney and bone and correlated to fluorescence intensity in the peripheral blood (reference sample).
Despite a reduction of mean arterial pressure from 100 to 80 mmHg bone blood flow remained constant. Further reduction of mean arterial pressure results in a linear decrease in bone blood flow.
The correlation between arterial pressure and organ perfusion in the bone is similar to blood flow within the kidney, indicating the presence of an autoregulated blood flow mechanism within the bone tissue.
各种器官的血流由自动调节机制决定，该机制可确保在动脉血压变化较大的范围内保持器官灌注稳定。这一生理原理已在肾脏、大脑和肠道得到证实，但迄今为止尚未在骨骼中得到证实。本研究旨在确定骨骼中是否存在自动调节机制。
使用荧光微球参考样本法来确定骨内和肾脏内的血流。在取出肾脏、股骨和胫骨之前，对 8 只麻醉的雌性新西兰兔进行了左心室荧光微球注射，微球注射范围涵盖了较宽的动脉血压水平。通过测量肾脏和骨骼中的荧光强度，并与外周血（参考样本）中的荧光强度相关联，来计算血流值。
尽管平均动脉压从 100mmHg 降至 80mmHg，骨血流仍保持不变。进一步降低平均动脉压会导致骨血流呈线性下降。
骨骼中的动脉压与器官灌注之间的相关性与肾脏内的血流相似，表明骨骼组织内存在自动调节的血流机制。
